Field of the Invention
The field of the present invention relates to a method and apparatus for repairing damaged, deteriorating, or fractured bones in the mid-foot region. More particularly, the present invention relates to both a method and device for treating the bones in the medial column of a human foot that are effected by Diabetic Charcot mid-foot collapse, LisFranc injuries, and the like.
Description of Related Art
The utilization of implants, such as intramedullary nails, rods, and screws is well known in the art, specifically in the treatment of long or large bone fractures. Implants are those devices which may be inserted into any foreign body, with intramedullary nails being the most common type of implant. Intramedullary nails have been limited in their application to long or large bones and such use has been widely known for long or large bones of the upper extremities (humerus, radius, ulna) and lower extremities (femur, tibia, fibula). Use of intramedullary nails allows physicians to secure fractured bones, maintain a desired length, and prohibit rotary motion while the bone heals and has time to rehabilitate. Intramedullary nails are also used for the fusion of bones.
Intramedullary nails are adapted for insertion into the medullary canal of a bone or bones, which may be reamed or left unreamed. Reaming is achieved by drilling out the medullary canal of the fractured or deteriorating bone, where the nail is inserted to stabilize and position the bone for healing. A cannulated reamer diameter generally runs in size from 7 mm and 18 mm, at increments of 0.5 mm. A medullary canal is generally reamed at 0.5 mm larger than the diameter of the nail to be inserted, so the bone is not damaged when the nail is inserted. Such reamers are well known by those with skill in the art.
Much of the prior art implant and intramedullary nail systems comprise intramedullary nails having fastener holes at both the proximal and distal ends for the insertion of fasteners, or locking screws. Fasteners include all attaching means by which an implant may be attached to bone. Such fasteners are inserted through a fastener hole or slot, also described as transfixation holes and screw holes. The use of locking screws is optional depending upon the severity of the bone damage. An intramedullary nail implanted with at least one fastener or locking screw both proximally and distally completely locks the nail in place (also known as static locking). Static locking neutralizes rotational stresses while preventing shortening of the limb. An intramedullary nail implanted with only one locking screw either proximally and distally, partially locks the nail (also known as dynamic locking). Dynamic locking neutralizes rotational stresses on one side of the fracture site while permitting axial loading. To surgically promote fusion of bone segments together, some means of static locking is required. Such holes and screws may also be adapted for the central portion of the nail or implant.
Several nails exist with fasteners or locking screws that are much longer in shape, described as lag screws, jigs, or nail heads, which further prevent the rotation of separated bones. Other nails have spacers to absorb stress associated with repetitive, natural impact. All such devices are focused on securing bone fragments during the process of fracture healing. Other methods for attaching the nail to the bone including the use of longitudinal pins, or the use of cement injected through a cannula in a nail to secure one end to the nail.
Various types of implants and intramedullary nails exist in the prior art, each composed of different materials and having different shapes with various degrees of functionality. Many nails are formed from either a slid rod metal or a more flexible sheet metal. Several nails have been proposed which form a rod material containing a central longitudinal bore disposed throughout (cannulated). Many nails have a number of longitudinal grooves cut along the rod (known as fluting), which allow for more rapid revascularization within the bone. Accordingly, nails made of various material and those having a differing array of shapes already exist and may be easily manufactured. A study of the geometrical properties of different nails is discussed in the article “Geometrical Properties and Torsional Fatigue Life of a Tibial Interlocking Intramedullary Nail Segment” Journal of Orthapedic Trauma, Vol. 12, No. 1, pp 8-15, and is incorporated herein. Also, different tibial nails were compared in the article “Biomechanical Study of Nine Different Tibia Locking Nails” Journal of Orthapedic Trauma, Vol. 10, No. I, pp 37-44, which is also incorporated herein.
Recently, implants and intramedullary nails are being fabricated using bioactive, biocompatible, and bioabsorbable material. Such nails are made from bioabsorbable polymers, copolymers, or polymer alloys that are self-reinforced containing ceramic particles or some type of reinforcement fibers. These implants and nails, as well as others, can also be made to be porous. The knowledge exists today to create human replica bones, grown in animals utilizing human gene technology, for ultimate use in humans, and such material may be a viable supplement for standard intramedullary nails of today. Such techniques should also be considered as an appropriate part of the present invention.
While there is much in the art regarding implants and intramedullary nails, there was no prior art found dealing directly with implants or intramedullary nails for the mid-foot region, or medial column of a human foot. Such a nail may likely have any or all of the similar properties, features, and characteristics of the above mentioned nails, but would have to be much smaller in length and thickness (for axial support) to accommodate the smaller bones of the mid-foot region. The prior art referring to intramedullary nails, for the most part, refers to nails which are used in much larger bones. Such art includes:
WO 00/72767 AI. The application describes an intramedullary nail for insertion within an intramedullary canal of a long bone and fixing a fracture in the long bone.
The nail comprises an elongate member with longitudinal axis, proximal and distal end, both of which have fastener receiving areas of at least one hole.
U.S. Pat. No. 6,406,477. The patent describes an intramedullary nail with a lag screw for connecting a bone portion separated from the femur, by fracture, to the main portion of the bone where such nail is capable of extending through both portions where a lag screw secures the nail.
WO 02/34107 A2. The Application describes an internal fixation device which utilizes a shaft within a sleeve wherein the shaft is movable within the sleeve along aligned slots.
U.S. Pat. No. 6,270,499 B1. The patent describes an intramedullary nail where the proximal end has at least one bore which extends transversely to the central axis of the nail for receiving at a stable angle a bone fastener.
U.S. Pat. No. 6,406,498 BI. The patent describes a device, such as an intramedullary nail or the like, which is fabricated using bioactive, biocompatible, and/or bioabsorbable material.
U.S. Patent Application No. US 2002/0029041 AI. The application describing an intramedullary nail formed with opposing dynamization windows and spacers of nonmetal material positioned within the windows to absorb stress transmitted through a fracture site.
U.S. Pat. No. 6,120,504. The patent describes an intramedullary nail with a longitudinal centerline extending between a proximal and distal end. The invention is directed to be interchangeably used in either a right or left limb, and to thus reduce the number of nail that must be inventoried at hospitals and other places utilizing intramedullary nails.
U.S. Pat. No. 4,705,027. The patent describes an intramedullary nail having a slot at the tip of the nail for engaging within the slot, a bolt previously inserted into the bone.
U.S. Pat. No. 5,658,287. The patent describes a locked intramedullary nail suitable for treating fractures of the femur.
U.S. Pat. No. 5,034,013. The patent describes an intramedullary nail having a tubular elongated body with grooves along the elongated body to allow for improved revascularization about the nail.
U.S. Pat. No. 5,766,174. The patent describes an intramedullary nail with an arcuate terminus tip, transverse holes for receiving fixation screws, and suture holes for the attachment of tissue.
U.S. Pat. No. 5,336,225. The patent describes device for reducing fractures, comprising a threaded screw.
U.S. Pat. No. 6,123,708. The patent describes a nail for axial insertion into a bone for support comprising a central bore through the nail body and a plurality of transverse holes throughout.
U.S. Pat. No. 5,814,047. The patent describes an intramedullary nail fixation apparatus having a plurality of equiangularly spaced piercing points.
U.S. Pat. No. 5,855,579. The patent describes a modular intramedullary nail having an open ended longitudinal bore, with connectable ends for elongating the nail.
E.P. 1 095626 AI. The patent describes a radial intramedullary nail.
U.S. Pat. No. 5,620,445. The patent describes a modular intramedullary nail with proximate, distal, and central components.
There is no known prior art relative to the use of intramedullary nails in the treatment of mid-foot bones or more specifically, treating the bones of the medial column. Most of the prior art describing the use of intramedullary nails is limited to methods for repairing large bones including, but not limited to the humerus, radius, ulna, femur, tibia, and fibula. Such art includes:
U.S. Pat. No. 6,019,761. The patent describes an intramedullary nail for implanting within a patient's long bone, and a method of use.
U.S. Pat. No. 5,201,735. The patent describes an apparatus such as a bone implant and method for implanting a bone implant or intramedullary rod for fixing a fracture of a bone.
U.S. Pat. No. 5,935,127. The patent describes a method for treating a fracture in a long bone by utilizing either a plate or intramedullary nail that spans the length of the bone.
U.S. Pat. No. 5,919,193. The patent describes a method for surgically correcting malformations in digits of a finger or toe by way of a one piece bone screw.
U.S. Pat. No. 4,976,712. The patent describes a method and apparatus for treating fractured bones by way of a bone screw.
The prior art relative to current treatments of mid-foot deformities, particularly those analogous to this type of treatment, are limited to:
“Charcot Ankle Fusion with a Retrograde Locked Intramedullary Nail” Foot & Ankle International, Vol. 18, No. 11, November 1997. This article focuses primarily on ankle fusion with a locked intramedullary nail, but specifies mid-foot deformity treatment to be limited to patient education, local foot-care, accommodative shoe gear, custom foot orthoses, and surgical correction.Additional articles of significance include; “Surgical Reconstruction of the Diabetic Foot: A salvage approach for mid-foot collapse” Foot Ankle Int., Early, J. S. and Hansen, S. T., 17:325-330, 1996 and “Arthrodesis as an Early Alternative to Nonoperative Management of Charcot Arthopathy of the Diabetic Foot”, The Journal of Bone and Joint Surgery, Inc., S. R. Simon Et AI., Vol. 82-A, No. 7, July 2000.“The Lateral Column Lengthening and Medial Column Stabilization Procedures” Clinical Orthopedics and Related Research, T. D. Chi Et al., No. 303, August 1999. Is an article that is the closest related study of surgical repair procedures to the present invention; however, it describes the use of multiple screws to secure the bones within the mid-foot which produced severely limited results.